Abstract: A first visual indicium (44) and a second visual indicium (50) are provided on a push rod (10) in an air operated diaphragm spring brake. The push rod (10) is mounted for reciprocal movement between an operative position and an inoperative position through an opening (26) in a service brake housing (16). The first indicium (44) comprises a discontinuity (45) in the surface of the push rod (10) having a leading edge (46) and grooves (48). The first indicium is positioned on the push rod such that the leading edge (46) will be exterior to the service chamber (12) only when the push rod is in the operative position and the brakes are substantially out of adjustment. The second visual indicium (50) comprises a second discontinuity formed of at least a leading edge (52) and a trailing edge (54). The second visual indicium (50) is positioned on the push rod whereby the trailing edge (54) will normally be exterior of the service chamber 12 adjacent the opening (26) when the push rod is in the inoperative position.

Abstract: An air-operated spring brake of the type wherein a spring-operated brake actuator is in tandem with an air-operated service brake actuator has a spring diaphragm which separates a spring housing into a fluid pressure chamber and a spring chamber. A spring in the spring chamber bears against a pressure plate to bias the diaphragm longitudinally in the spring housing in a brake-applying direction upon a decrease in pressure in the fluid pressure chamber. The diaphragm is movable generally longitudinally in the other direction to compress the spring in the presence of pressure in the fluid chamber to allow operation of the service brake actuator independently of the spring-operated actuator. A push plate, mounted to a push member, moves reciprocally with the diaphragm in the fluid pressure chamber in abutting relationship to the spring diaphragm.

Abstract: A vehicle suspension element adjustment apparatus including improved structure for adjusting suspension elements to any of a plurality of discrete positions for alignment thereof wherein pairs of relatively adjustable elements are connected to respective pairs of plate members having formed surfaces for mutual interengagement of the pairs of plates in any of such discrete positions of adjustment. The formed surfaces preferably are vertically oriented serrations which permit relative horizontal adjustment between the pairs of plates, and hence between the suspension elements connected thereto.